979 resultados para cocoa plantation


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Diaphorina citri es vector de la bacteria que produce la enfermedad HLB en cítricos, una de las más destructivas. En lotes comerciales de naranja dulce en Entre Ríos se analizó la abundancia espacio-temporal de adultos de D. citri y del ectoparasitoide Tamarixia radiata. Quincenalmente y durante tres años se colectaron adultos en 10 trampas cromotrópicas y los datos obtenidos fueron relacionados con el porcentaje medio de brotación de otra plantación. El número de D. citri/trampa/quincena se analizó mediante Kruskal-wallis y prueba de Mantel y la respuesta de agregación de T. radiata mediante correlación. Ambas poblaciones exhibieron la mayor abundancia el primer año: las frecuentes aplicaciones de abamectina en el segundo y tercero provocaron una marcada reducción. Espacialmente, la diferencia numérica de D. citri entre árboles no estuvo asociada a su cercanía pero la correlación entre ellos fue significativa. Temporalmente se evidenciaron cuatro picos de abundancia: tres asociados a brotación (invernal, primaveral y estival), y un cuarto no asociado a brotación. La mayor abundancia de T. radiata ocurrió en los árboles con mayor abundancia de D. citri y hubo una significativa correlación espacial entre ambas especies. El enrollamiento anti-horario del gráfico entre D. citri - T. radiata en árboles individuales sugiere una interacción huésped- parasitoide, estructurada como poblaciones locales.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El presente trabajo propone una lectura del ensayo central de Antonio Benítez Rojo La isla que se repite (1989), insoslayable para abordar y reflexionar sobre las culturas caribeñas, procurando delinear una posible interpretación de la relación entre su poética y el exilio como así también analizar algunas de las elecciones que hizo como intelectual, y el modo en que imaginó el Caribe en sus ensayos. En el mapa elaborado por Benítez Rojo las islas paradisíacas figuran junto a las dominadas por la violencia y la muerte, y a veces se confunden. La Plantación y la Utopía son los temas principales. Los ensayos de La isla que se repite permiten examinar su deseo de anudarse a otras tradiciones mediante un largo rodeo a través de las ricas matrices culturales del Caribe. Fue su modo de escapar y trascender el discurso autoritario de la "nación" dominante en la historia moderna cubana.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El presente trabajo propone una lectura del ensayo central de Antonio Benítez Rojo La isla que se repite (1989), insoslayable para abordar y reflexionar sobre las culturas caribeñas, procurando delinear una posible interpretación de la relación entre su poética y el exilio como así también analizar algunas de las elecciones que hizo como intelectual, y el modo en que imaginó el Caribe en sus ensayos. En el mapa elaborado por Benítez Rojo las islas paradisíacas figuran junto a las dominadas por la violencia y la muerte, y a veces se confunden. La Plantación y la Utopía son los temas principales. Los ensayos de La isla que se repite permiten examinar su deseo de anudarse a otras tradiciones mediante un largo rodeo a través de las ricas matrices culturales del Caribe. Fue su modo de escapar y trascender el discurso autoritario de la "nación" dominante en la historia moderna cubana.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabajo se propone analizar el intertexto que une al escritor Edouard Glissant con William Faulkner a través de dos obras: el ensayo Faulkner, Mississipi (1996) y la novela Sartorius (1999). En el primer texto, el autor enfatiza cuestiones presentes en su propia obra novelesca: la genealogía, la relación con el espacio de la plantación, el mestizaje, la (i)legitimidad de derechos con respecto a la posesión de la tierra, la opacidad. En el segundo, traza una línea genealógica de un personaje perteneciente a una etnia africana imaginaria, haciéndolo llegar hasta las plantaciones del sur de los Estados Unidos; paralelamente, presenta la línea genealógica de los Sartoris. En esta dirección, busco mostrar cómo el proyecto literario de Glissant dialoga con la obra de Faulkner, indagando e inventariando las mismas problemáticas con respecto al transplante de poblaciones y su inserción en el espacio de las plantaciones, tanto en el sur de los Estados Unidos como en las islas del Caribe. En las obras de ambos escritores puede percibirse el mismo vértigo trágico que persigue a los personajes, conduciéndolos a la locura, el sufrimiento y la muerte

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El presente trabajo propone una lectura del ensayo central de Antonio Benítez Rojo La isla que se repite (1989), insoslayable para abordar y reflexionar sobre las culturas caribeñas, procurando delinear una posible interpretación de la relación entre su poética y el exilio como así también analizar algunas de las elecciones que hizo como intelectual, y el modo en que imaginó el Caribe en sus ensayos. En el mapa elaborado por Benítez Rojo las islas paradisíacas figuran junto a las dominadas por la violencia y la muerte, y a veces se confunden. La Plantación y la Utopía son los temas principales. Los ensayos de La isla que se repite permiten examinar su deseo de anudarse a otras tradiciones mediante un largo rodeo a través de las ricas matrices culturales del Caribe. Fue su modo de escapar y trascender el discurso autoritario de la "nación" dominante en la historia moderna cubana.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We integrate upper Eocene-lower Oligocene lithostratigraphic, magnetostratigraphic, biostratigraphic, stable isotopic, benthic foraminiferal faunal, downhole log, and sequence stratigraphic studies from the Alabama St. Stephens Quarry (SSQ) core hole, linking global ice volume, sea level, and temperature changes through the greenhouse to icehouse transition of the Cenozoic. We show that the SSQ succession is dissected by hiatuses associated with sequence boundaries. Three previously reported sequence boundaries are well dated here: North Twistwood Creek-Cocoa (35.4-35.9 Ma), Mint Spring-Red Bluff (33.0 Ma), and Bucatunna-Chickasawhay (the mid-Oligocene fall, ca. 30.2 Ma). In addition, we document three previously undetected or controversial sequences: mid-Pachuta (33.9-35.0 Ma), Shubuta-Bumpnose (lowermost Oligocene, ca. 33.6 Ma), and Byram-Glendon (30.5-31.7 Ma). An ~0.9 per mil d18O increase in the SSQ core hole is correlated to the global earliest Oligocene (Oi1) event using magnetobiostratigraphy; this increase is associated with the Shubuta-Bumpnose contact, an erosional surface, and a biofacies shift in the core hole, providing a first-order correlation between ice growth and a sequence boundary that indicates a sea-level fall. The d18O increase is associated with a eustatic fall of ~55 m, indicating that ~0.4 per mil of the increase at Oi1 time was due to temperature. Maximum d18O values of Oi1 occur above the sequence boundary, requiring that deposition resumed during the lowest eustatic lowstand. A precursor d18O increase of 0.5 per mil (33.8 Ma, midchron C13r) at SSQ correlates with a 0.5 per mil increase in the deep Pacific Ocean; the lack of evidence for a sea-level change with the precursor suggests that this was primarily a cooling event, not an ice-volume event. Eocene-Oligocene shelf water temperatures of ~17-19 °C at SSQ are similar to modern values for 100 m water depth in this region. Our study establishes the relationships among ice volume, d18O, and sequences: a latest Eocene cooling event was followed by an earliest Oligocene ice volume and cooling event that lowered sea level and formed a sequence boundary during the early stages of eustatic fall.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We investigated the local bird community in Central Sulawesi (Indonesia), with focus on insectivorous species in the agroforestry landscapes adjacent to the Lore Lindu National Park. All study sites were situated at the northern tip of Napu Valley in Central Sulawesi, Indonesia. After an initial mapping of the study area, we selected 15 smallholder cacao plantations as sites for our study in March 2010. These sides were mainly used for bird and bat exclosure experiments. All sited were situated along a local gradient (shade availability on each plantation) and a landscape gradient (distance to primary forest), which were independent from each other. In September 2010 and from February until June 2011, we assessed the bird community on our 15 study sites using monthly point count and mist netting sampling. Point count (20 minutes between 07 am and 10 am and in between the net checking hours) and mist netting surveys (12 hours, between 05:30 am and 17:30 pm) were conducted simultaneously but only once per month on each study site, to avoid habituation of the local bird community to our surveys. Further, point counts were conducted at least 100 m apart from the mist netting sites, to avoid potential disturbance between the two methods. We discarded all observations beyond 50 m (including those individuals that flew over the canopy) from the statistical analysis, as well as recaptures of individuals within identical mist netting rounds.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lobsigensee is a small kettle hole lake 15 km north-west of Bern on the Swiss Plateau, at an altitude of 514 m asl. Its surface is 2ha today, its maximum depth 2.7 m; it has no inlet and the overflow functions mainly during snow melting. The area was covered by Rhone ice during the Last Glaciation (map in Fig.2). Local geology, climate and vegetation are summarized in Figure 3A-C, the history of settlement in Figures 5-7. In order to reconstruct the vegetational and environmental history of the lake and its surroundings pollen analysis and other bio- and isotope stratigraphies were applied to twelve profiles cored across the basin with modified Livingstone corers (Fig.3 D). (1) The standard diagram: The central core LQ-90 is described as the standard pollen diagram (Chapter 3) with 10 local pollen assemblage zones of the Late-Glacial (local PAZ Ll to Ll0, from about 16'000(7) to 10'000 years BP) and 20 PAZ of the Holocene (local PAZ L11 to L30), see Figs. 8-10 and 20-24. Local PAZ L 1 to L3 are in the Late-Glacial clay and record the vegetational development after the ice retreat: L1 shows very low pollen concentration and high Pinus percentages due to long-distance transport and reworking; the latter mechanism is corroborated by the findings of thermophilous and pre-Quaternary taxa. Local PAZ L2 has a high di versi ty of non-arboreal pollen (NAP) and reflects the Late-Glacial steppe rich in heliophilous species. Local PAZ L3 is similar but additionally rich in Betula nana and Sal1x, thus reflecting a "shrub tundra". The PAZ L1 to L3 belong to the Oldest Dryas biozone. Local PAZ L4 to L 10 are found in the gyttja of the profundal or in the lake marl of the littoral and record the Late-Glacial forests. L4 is the shrub phase of reforestation with very high Junlperus and rapidly increasing Betula percentages. L5 is the PAZ with a first, L7 with a second dominance of tree-birches, separated by L6 showing a depression in the Betula curve. L4 to L7 can be assigned to the Balling biozone. Possible correlation of the Betula depression to the Older Dryas biozone is discussed. In local PAZ L8 Plnus immigrates and expands. L9 shows a facies difference in that Plnus dominates over Betula in littoral but not in profundal spectra. L8 and L9 belong to the Allerod biozone. In its youngest part the volcanic ash from Laach/Eifel is regularly found (11,000 BP). The local PAZ Ll0 corresponds to the Younger Dryas blozone. The merely slight increase of the NAP indicates that the pine forests of the lowland were not strongly affected by a cooler climate. In order to evaluate the significance of the littoral accumulation of coniferous pollen the littoral profile LQ-150 is compared to the profundal. Radiocarbon stratigraphies derived from different materials are presented in Figures 13 and 14 and in Tables 2 and 3. The hard-water errors in the gyttja samples and the carbonate samples are similar. The samples of terrestrial plant macrofossils are not affected by hard-water errors. Two plateaux of constant age appear in the age-depth relationship; their consequence for biostratigraphy as well as pollen concentration and influx diagrams are discussed. Radiocarbon ages of the Late-Glacial pollen zones are shown in Table 10. The Holocene vegetational history is recorded in the local PAZ L 11 to L30. After a Preboreal (PAZ L11) dominated by pine and birch the expansions of Corylus, Ulmus and Quercus are very rapid. Among these taxa Corylus dominates dur ing the Boreal (PAZ L 12 and L 1 3), whereas the components of the mixed oak forest dominate in the Older Atlantic (PAZ L14 to L16). In the Younger Atlantic (PAZ L 17 to L 19) Fagus and Alnus play an increasing, the mixed oak forest a decreasing role. During the period of local PAZ L19 Neolithic settlers lived on the shore of Lobsigensee. During the Subboreal (PAZ L20 and L21) and the Older Subatlantic (L22 to L25) strong fluctuations of Fagus and often antagonistic peaks of NAP, Alnus, Betula and Corylus can be interpreted as signs of human impact on vegetation. L23 is characterized not only by high values of NAP (especially apophytes and anthropochorous species) but also by the appearance of Juglans, Castanea and Secale which point to the Roman colonization of the area. For a certain period during the Younger Subatlantic (PAZ L26 to L30) the lake was used for retting hemp (Cannabis). Later the dominance of Quercus pollen indicates the importance of wood pastures. The youngest sediments reflect the wide-spread agricultural grass lands and the plantation of Pinus and Picea. Radiocarbon dates for the Holocene are given in Figure 23 and Table 4, the extrapolated ages of the Holocene pollen zones in Table 15. (2) The cross sections: Figures 25 and 26 give a summary of the litho- and palynostratigraphy of the two cross sections. Based on 11 Late-Glacial and 9 Holocene pollen diagrams (in addition to the standard ones), the consistency of the criteria for the definition of the pollen zones is examined in Tables 7 and 8 for the Late-Glacial and in Tables 11 to 14 for the Holocene. Sediment thicknesses across the basin for each pollen zone are presented in these tables as well as in Figures 43 to 45 for the Late-Glacial and in Figures 59 to 65 for the Holocene. Sediment focusing can explain differences between the gyttja cores of the profundal. Focusing is more than compensated for through "stretching" by carbonate precipitation on the littoral terrace. Pollen influx to the cross section are discussed (Chapters 4.1.5. and 4.2.3.). (3) The regional pollen zones: Based on some selected sites between Lake Geneva and Lake Constance regional pollen zones are proposed (Table 16, 17 and 19). (4) Paleoecology: Climatic change in the Late-Glacial can be inferred from Coleoptera, Trichoptera, Chironomidae and d18O of carbonates: a distinct warming is recorded around 12' 600 BP and around 10' 000 BP. The Younger Dryas biozone (10'700-10'000 BP) was the only cooling found in the Late-Glacial. The Betula depression often correlated wi th the Older Dryas biozone was possibl not colder but dryer than the previous period. During the Holocene the lowland site is not very sensitive to the minor climatic changes. Table 22 summarizes climatic and trophic changes before 8'000 BP as deduced from various biostratigraphies studied by a number of authors. Ostracods, Chironomids and fossil pigments indicate that anoxic conditions prevailed during the BoIling (possibly meromixis). Changes in the lake level are illustrated in Figure 74. A first lake-level lowering occurred in the early Holocene (10'000 to 9'000 BP), a second during the Atlantic (about 6'800 to 5'200 BP). The first "shrinking" of the lake volume resulted in a eutrophication recorded by laminations in the profundal and by pigments of Cyanophyceae. The second fall in water level corresponds to an increase of Nymphaeaceae. Human impact can be inferred in three ways: eutrophication of the lake (since the Neolithic), changes of terrestrial vegetation by deforestations (cyclicity of Fagus, see Figures 78 to 80), and enhanced erosion (increasing sedimentation rates by inwashed clay, particularly since the Roman Colonization, see Figures 49 and 81). Summary: This paper was planned as the final report on Lobsigensee. However, a number of issues are not answered but can only be asked more precisely, for example: (1) For the two periods with the highest rates of change, Le. the Bolling and the Preboreal biozones, pollen influx may reflect vegetation dynamics. Detailed investigations of these periods in annually laminated sediments are planned. (2) Biostratigraphies other than palynostratigraphy are needed to estimate the degree of linkage or independence in the development of terrestrial and lacustrine ecosystems. Often our sampling intervals were not identical, thus influencing our temporal resolution. (3) 6180- and 14C-stratigraPhies with high resolution will elucidate the leads and lags of these dynamic periods. Plateaux of constant age in the age-depth relationship have a strong bearing on both biological and geophysical understanding of Late-Glacial and early Holocene developments. (4) Numerical methods applied to the pollen diagrams of the cross section will help to quantify the significance of similari ties and dissimilarities across a single basin (with Prof. Birks). (5) Numerical methods applied to different sites on the Swiss Plateau and on the transect across the Alps will be helpful in evaluating the influence of different environmental factors (with Prof. Birks). (6) A new map 1: 1000 with 50cm-contour lines prov ided by Prof. Zurbuchen will be combined with a grid of cores sampling the transition from lake marl to peat enabling us to calculate paleo-volumes of the lake. This is interesting for the two "shrinking periods" (in Fig. 74A numbers 2-6 and 7-10), both accompanied by eutrophication. The pal eo-volume during the Neoli thic set tlement of the Cortaillod culture linked wi th an est l.mate of trophic change derived from diatoms (Prof. Smol in prep.) could possibly give an indication of the size of the human population of this period. (7) For the period with the antagonism between Fagus peaks and ABC-peaks close collaboration between palynologists, geochemists and archeologists should enable us to determine the influence of prehistoric and historic people on vegetation (collaboration with Prof. Stockli and Prof. Herzig). (8) The core LL-75 taken with a "cold letter box" will be analysed for major and trace elements by Dr. Sturm for 210pb and 137Cs by Prof.von Gunten and for pollen. We will see if our local PAZ L30 really corresponds to the surface sediment and if the small seepage lake reflects modern pollution.